Threaded holes are common in machinery and mechanical apparatus, such as spark plug holes in an engine block, plumbing holes and tank holes, stud holes, and the like. The threads can become damaged during use, and if this occurs, repairs are often difficult or impossible. Bolts and other fasteners cannot be securely threaded into hoes with damaged threads, which can result in scrapping of expensive machinery.
A variety of techniques are known for creating threads in a hole or repairing damaged threads, such as those described in U.S. Pat. Nos. 4,090,808; 0,637,718; 0,188,466; 5,718,636; 4,661,028; 5,281,059; 1,217,833; 1,890,052; 6,565,297; 5,803,676; 2,949,618; 1,509,438; 0,876,964; 1,075,753 and 2,284,768. However, these techniques suffer from one or more of the following disadvantages, namely inapplicability to use in blind holes, inability to adjust to different sized holes, complexity, difficult to use, cost, and inability to repair threads in large sized holes.
Therefore there is a need for a thread repair system that overcomes the deficiencies of the prior art.